Athletes who will complete in the Olympics intensified their training, and it certainly looks like they went to the right people to do that.

Members of the U.S. Sailing Team as well as other athletes trained with the U.S. Navy SEALs in Colorado Springs, who pushed them even further. This isn’t the first time that Olympic athletes are working with the SEALs, although they usually go to San Diego to do that.

Before they went to Pikes Peak to train, the athletes were shown a video of the Navy SEALs’ Hell Week, in order to get a preview of what they will be going through. Once there, the SEALs had the athletes do nearly 100 push-ups and then run into a freezing pond – not just once, but several times.

They were also made to lift 220 pounds of wood, and carry it across the park.

Anna Tunnicliffe of the Sailing Team shared: Swimming in freezing cold water then coming out and standing around in a 15 knot freezing cold wind took you to a new limit.

Just like BUD/S, not everyone was able to hurdle the physical and mental challenges of the first day. Only 18 of the 42 athletes who began the training remained after two hours.

The SEALs, however, were not one to give up that easy; everyone, including those who dropped out the previous day, were called back to the line the following day.

Paige Railey, also of the Sailing Team, said: “Swimming in freezing cold water then coming out and standing around in a 15 knot freezing cold wind took you to a new limit.”